A three-pronged drought scenario continued across the contiguous U.S. during the past month, with drought conditions expanding across the Four Corners states following a lackluster Monsoon, short term drought continuing across the southern Plains with a westward shift in the most intense areas, and widespread late Summer flash drought conditions beginning to ease across the Ohio Valley and Mid-Atlantic.
In contrast, flash drought conditions continued to expand across southeastern Alabama and the Florida Panhandle, parts of Georgia, and upland South Carolina. Towards the end of the month, frigid Canadian air invaded the western and central parts of the U.S., with frontal systems pulling moisture from the Gulf of Mexico (and a pair of weak tropical cyclones) and generating widespread precipitation across the eastern U.S., while record warmth and relative dryness persisted across Florida and other parts of the Southeast.
During November, the rapidly declining sun angle and temperatures, along with vegetative dormancy, provide a prime opportunity for soil moisture recharge. Early in the month, widespread precipitation is forecast across the mid-Atlantic and Northeast ahead of a potent cold front, followed by a period of cold weather across much of the central and eastern U.S. Enhanced precipitation along the southern edge of the cold high pressure is favored for Texas, the Deep South, and the South Atlantic during Week-2.
For the latter half of November, dynamical models generally favor a de-amplification of the pattern with increasing uncertainty. Based on recent rainfall and the potential for widespread additional precipitation, continued drought reduction is favored for the Southern Plains and much of the East.
Drought persistence seems like the most likely outcome for Florida and southern Georgia, however, where precipitation deficits persist and the short term forecasts indicate lighter accumulations. Persistence is also favored for the Four Corners region, where climatological precipitation is low and the updated CPC November outlook favors below-median precipitation.
Despite the ongoing wildfires in California and widespread above-normal temperatures, early season snowpack and reservoir conditions across the West remain in good shape, and drought development is not anticipated.
Continued drought improvement across Hawaii may be limited to the central islands, and while climatological precipitation increases across the Alaska Panhandle this time of year, the absence of a clear wet signal limits prospects for widespread improvement of the long term drought conditions.
Forecast confidence is moderate for the Southeast Region.
- During the latter half of October, frontal intrusions brought periods of rainfall to the Southeast, drawing Gulf Moisture northward including two brief tropical cyclones: Tropical Storm Nestor and Tropical Storm Olga. These rains helped ease short term drought conditions that developed during late Summer and early Fall across western Alabama and the southern Appalachians through Virginia.
- Flash drought conditions, aggravated by persistently above-normal temperatures, continued to deteriorate across areas that received less precipitation, however, including parts of the Florida Panhandle, southeastern Alabama, and the Piedmont of Georgia and South Carolina.
- At the end of October, a potent cold front brought widespread rainfall to much of the Southeast, with the heaviest accumulations again falling across western Alabama through the southern Appalachians.
- Continued light to moderate rainfall is expected to continue in the near term across the region, and the CPC 8-14 day outlook favors above-median precipitation due to the anticipated presence of a persistent frontal boundary. Climatology provides a limiting factor on the speed of further drought deterioration as well.
- Based on recent rainfall and the anticipated continued wetness through the first half of November, drought reduction is favored for much of the Southeast. Drought persistence seems like the most likely outcome for southern Georgia and north-central and northeastern Florida, however, where both recent rainfall and forecasted accumulations are more meager and above-normal temperatures are favored to linger. The potential for wetness in Week-2 precludes the inclusion of any further areas of development.
Forecast confidence is low to moderate for the Southern Region.
- Across the Southern Region, widespread heavy rainfall associated with frontal passages and tropical cyclone activity eased drought conditions across Louisiana, Arkansas, and northeastern Texas, while a potent early season winter storm brought widespread snow to North Texas. Between these regions, precipitation was spottier across central Texas, and short term drought conditions generally degraded more than they improved.
- During November, dynamical model forecasts and the CPC 8-14 day outlook both show the potential for a widespread precipitation event across the Southern Plains along a boundary between cold, dry Canadian air and Gulf moisture. The updated CPC monthly outlook has enhanced chances for above-median precipitation across western Texas.
- Based on these outlooks, drought improvement is favored, though areas of drought are likely to remain through the end of the month.
Forecast confidence is high for the Midwest Region.
- Increased precipitation and decreased temperatures in October eased widespread flash drought conditions that developed across the Midwest during late Summer and early Fall.
- Small areas of drought remain across parts of the Ohio River Valley, particularly in Ohio.
- November typically presents a good opportunity for soil moisture recharge across the region, with vegetation entering dormancy, decreasing sun angles and temperatures, and a fairly wet climatology.
- A strong cold front crossing the region during late October has brought widespread heavy precipitation, with unseasonably cold temperatures anticipated through the first half of November. As this moisture works its way into the soils and streams, further drought reduction is favored.
- The updated CPC monthly outlook maintains equal chances for below-, near-, and above-median precipitation and enhanced chances for below-normal temperatures. Based on recent rainfall, these outlooks, and climatology, the Midwest region is favored to be drought free by the end of the month.
Forecast confidence is high for the Western and High Plains Regions.
- Drought conditions continued to degrade across the Four Corners region during October following a below-average Monsoon season, particularly across central Utah, parts of Colorado, and northeastern New Mexico.
- In contrast, winter storm activity brought improvements to southern New Mexico and the higher elevations of northern Colorado.
- The Pacific West is currently drought free, with snowpack conditions across the Cascades and northern Sierra Nevadas, as well as California reservoir levels, in good shape for this time of year.
- Despite the adequate hydrologic situation, above-normal temperatures and periods of high winds have contributed to widespread devastating wildfire activity across California.
- Soil moisture remains abundant to excessive across the Northern Plains.
- The updated CPC November outlook favors below-median precipitation from Northern California eastward to western Colorado. This forecast, coupled with a drier climatology for the interior West during November, makes drought improvement across the Four Corners unlikely. Therefore, persistence is favored, but no additional development is anticipated as temperatures decrease and the wet season begins ramping up across the Pacific coast.
Forecast confidence is high for the Northeast Region.
- Rainfall began to pick up across the Northeast Region in late October, with reduced temperatures behind several cold fronts. These conditions eased drought, and there is no drought currently in place.
- A strong cold front is crossing the Northeast in the near term, with below-normal temperatures favored through the first half of November in its wake. Given the reduced temperatures and generally wet climatology, redevelopment of drought is not anticipated.
Forecast confidence is moderate for Alaska, Hawaii, and Puerto Rico.
- Above-average rainfall has improved drought conditions across southern Alaska, though longer term drought conditions persist across the Panhandle. The updated CPC November outlook favors increased chances for above-median precipitation across southern Alaska, so removal of the small remaining drought area near the Kenai Peninsula is anticipated. While climatological precipitation increases across the Panhandle during November, confidence remains too low to favor improvement of longer term drought conditions.
- For Hawaii, dynamical model forecasts generally favor above-median precipitation across the northwestern islands, with near to below-normal rainfall to the southeast. Therefore, further drought improvements ahead of the wet season are limited to Lanai and Molokai.
- As of the latest U.S. Drought Monitor, Puerto Rico is now free of moderate drought conditions, and drought redevelopment is not anticipated during November.